I'm gonna try and find you some links to Adyashanti's meditation technique one second. Also don't let Adyashanti and Eckhart Tolle's new age reputation worry you. Really good info, just psychology really.The more energy you give to thoughts the more prevalent and more powerful they become. You must not feed them any more energy. The key to living in the now is to allow everything to be as it is. Don't resist anything mentally. Don't project into the future in attempt to escape an unpleasant now. Just be still. Feeling anxious? Allow yourself to feel anxious, don't try and escape it. Treat every moment as if you had chosen it. Totally surrender to whatever you are feeling, even if it is very negative, when you are completely surrendered then there is no conflict, no projection, no trying to escape, no more negative thoughts (which trigger even more negative thoughts and negative emotions which trigger negative thoughts etc.) There are two methods that I use to try to become more present if I am dwelling on things from the past. The first is to just watch your thoughts. Don't identify with them. Don't judge them. Just watch them. Observe them, realize that they are not you, they are just a matrix of repetitive conditioned thought loops. Gradually they will start to lose power over you and will no longer make emotional connections which trigger negative emotions and other thought loops. Another method is to consciously put your attention into the present moment. Try to feel your body from the inside and any sensations. Listen to the noises around you. Put your attention on your breathing etc. I alternate between these and others though. I find the 'allowing everything to be as it is' method the best though because you are not trying to get anywhere (which is projection, the false belief that you need to 'get somewhere' to feel complete and in the now, sometimes I got myself into bad mental states trying to hard to be in the now, so completely surrendering to the present moment and your emotions whatever they may be is best, you will sort of figure it out though through trial and error)
Read the book "The Power of Now." I like the audiobook. You can listen to it when you are going to sleep. I've listened to it like 20 times now and I think its a goldmine. I used to really be into it for about 3-4 months and I changed drastically and my normal state of consciousness drastically changed while I was doing it. I became very relaxed and calm and had very little mental static or repetitive thoughts that I have when I am anxious. The only problem is disciplining yourself into meditating and practicing the techniques etc. I actually kept a journal and wrote down how I was feeling periodically throughout the day. When I first was getting started I was only like a 4/10. So a constant state of physical discomfort caused by anxiety and a negative state of consciousness. I quickly started averaging about a 7.5/10. Some times I'd feel really good like a 9/10. I also wrote down all sorts of experiences I had while meditating and just trying out the techniques. What worked and what didn't also a bunch of insights into the mind. Also I had some really vivid and amazing dreams during this whole process. I also had incredible motivation during this and got into very good shape in a short amount of time. I went from barely being able to run 1 mile to running 10 in about 2 months. Also quit smoking and caffeine during this time. Since then though I lost motivation and am doing pretty crappy again. I'm gonna start up again and attempt one last physical and mental transformation. This time I'm gonna get a job when I get back to feeling a 7.5/10. I think thats what screwed me last time is that I never got a job.
Also I almost completely stopped using the internet during this time. The internet is an addiction that gives me anxiety and puts me into slightly negative states of mind. I also meditated for sometimes like 6 hours a day. Though usually only like 2 hours or so. You only need to for about 30 minutes or so imho. Do it right when you wake up. Helps center yourself and start off the day in a positive mental state and is therefore much easier to maintain throughout the day. Sometimes I would wake up and feel like a 4/10 and then after 40 minutes of meditation I would be at like a 7/10 or so. Once you 'level yourself up' through meditation you will be able to maintain it throughout most of the day. Sometimes its hard to get into the 'now' and into a better frame of mind but when you actually do it its easy to maintain to a large extent.